import math;
class c():
    def __init__(self):
        self.x=1
    def __getitem__(self, idx):
        return  getattr(self, idx);
    def __setitem__(self, idx, val):
        setattr(self, idx,val);


if __name__ == '__main__':
    a=c();
    print(a.x)
    print(a['x'])
    avg=sum()
    print(math.pow(avg,2))